Kafelnikov, who disposed of the Dutch 11th seed, Richard Krajicek, 6-3, 6-2 in another quarter-final, is sure to provide even tougher opposition for the defending champion, whose game is best suited to faster surfaces.
'It is not going to be easy,' Stich said. 'He is in very good form and it is going to be a very difficult match.' Kafelnikov, who has risen from 104th to 29th in the world rankings this year, beat Stich on clay at the Monte Carlo Open last month and has already defeated the third seed, Goran Ivanisevic, in Hamburg.
Stich has lost three out of four matches with the hard-hitting Russian in the last year, two of which were on clay. The 20-year-old Kafelnikov is living up to the perhaps obvious comparison with a Kalashnikov rifle, which he admits he likes.
'It is the best gun in the world,' he said. 'I am getting real satisfaction at the moment. I did not expect to beat Goran Ivanisevic. I feel confident.'
Stich had to work hard to beat Costa, who saved a match point when he was 5-4 down in the second set and then forced a third set by winning the tie- break 7-3.
Earlier, the Spaniard, Javier Sanchez, also reached the semi-finals with a 6-4, 6-2 victory over the Dutchman Jacco Eltingh. Sanchez will play Andrei Medvedev, the fourth seed, who beat Swedish fifth seed Magnus Gustafsson 6-4,
4-6, 6-1 in the last quarter-final.Reuse content